如何在MOB树的每个节点中找到观测值？ （partykit软件包）

Question

I have used the partykit package to create a Model-Based Partitioning (MOB) tree on a dataset and I wondered if there was a way to see which observations in our dataset pass that rules and fall in each node. (I want to have separate data frame for each node base on the tree rules).

Answer 1

You can use predict(..., type = "node") for all partykit trees to obtain the predicted terminal node ID. And then you can use that for split() ting the data set. For example:

library("partykit")
tr <- lmtree(dist ~ speed, data = cars)
plot(tr)

split(cars, predict(tr, type = "node"))
## $`3`
##    speed dist
## 1      4    2
## 2      4   10
## 3      7    4
## 4      7   22
## 5      8   16
## 6      9   10
## 7     10   18
## 8     10   26
## 9     10   34
## 10    11   17
## 11    11   28
## 12    12   14
## 13    12   20
## 14    12   24
## 15    12   28
## 
## $`4`
##    speed dist
## 16    13   26
## 17    13   34
## 18    13   34
## 19    13   46
## 20    14   26
## 21    14   36
## 22    14   60
## 23    14   80
## 24    15   20
## 25    15   26
## 26    15   54
## 27    16   32
## 28    16   40
## 29    17   32
## 30    17   40
## 31    17   50
## 
## $`5`
##    speed dist
## 32    18   42
## 33    18   56
## 34    18   76
## 35    18   84
## 36    19   36
## 37    19   46
## 38    19   68
## 39    20   32
## 40    20   48
## 41    20   52
## 42    20   56
## 43    20   64
## 44    22   66
## 45    23   54
## 46    24   70
## 47    24   92
## 48    24   93
## 49    24  120
## 50    25   85